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tools/cub-1.8.0/test/test_device_reduce.cu 48.7 KB
8dcb6dfcb   Yannick Estève   first commit
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  /******************************************************************************
   * Copyright (c) 2011, Duane Merrill.  All rights reserved.
   * Copyright (c) 2011-2018, NVIDIA CORPORATION.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in the
   *       documentation and/or other materials provided with the distribution.
   *     * Neither the name of the NVIDIA CORPORATION nor the
   *       names of its contributors may be used to endorse or promote products
   *       derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   ******************************************************************************/
  
  /******************************************************************************
   * Test of DeviceReduce utilities
   ******************************************************************************/
  
  // Ensure printing of CUDA runtime errors to console
  #define CUB_STDERR
  
  #include <stdio.h>
  #include <limits>
  #include <typeinfo>
  
  #include <thrust/device_ptr.h>
  #include <thrust/reduce.h>
  
  #include <cub/util_allocator.cuh>
  #include <cub/device/device_reduce.cuh>
  #include <cub/device/device_segmented_reduce.cuh>
  #include <cub/iterator/constant_input_iterator.cuh>
  #include <cub/iterator/discard_output_iterator.cuh>
  #include <cub/iterator/transform_input_iterator.cuh>
  
  #include "test_util.h"
  
  using namespace cub;
  
  
  //---------------------------------------------------------------------
  // Globals, constants and typedefs
  //---------------------------------------------------------------------
  
  int                     g_ptx_version;
  int                     g_sm_count;
  bool                    g_verbose           = false;
  bool                    g_verbose_input     = false;
  int                     g_timing_iterations = 0;
  int                     g_repeat            = 0;
  CachingDeviceAllocator  g_allocator(true);
  
  
  // Dispatch types
  enum Backend
  {
      CUB,            // CUB method
      CUB_SEGMENTED,  // CUB segmented method
      CUB_CDP,        // GPU-based (dynamic parallelism) dispatch to CUB method
      THRUST,         // Thrust method
  };
  
  
  // Custom max functor
  struct CustomMax
  {
      /// Boolean max operator, returns <tt>(a > b) ? a : b</tt>
      template <typename OutputT>
      __host__ __device__ __forceinline__ OutputT operator()(const OutputT &a, const OutputT &b)
      {
          return CUB_MAX(a, b);
      }
  };
  
  
  //---------------------------------------------------------------------
  // Dispatch to different CUB DeviceReduce entrypoints
  //---------------------------------------------------------------------
  
  /**
   * Dispatch to reduce entrypoint (custom-max)
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT, typename ReductionOpT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      ReductionOpT        reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      typedef typename std::iterator_traits<InputIteratorT>::value_type InputT;
  
      // The output value type
      typedef typename If<(Equals<typename std::iterator_traits<OutputIteratorT>::value_type, void>::VALUE),  // OutputT =  (if output iterator's value type is void) ?
          typename std::iterator_traits<InputIteratorT>::value_type,                                          // ... then the input iterator's value type,
          typename std::iterator_traits<OutputIteratorT>::value_type>::Type OutputT;                          // ... else the output iterator's value type
  
      // Max-identity
      OutputT identity = Traits<InputT>::Lowest(); // replace with std::numeric_limits<OutputT>::lowest() when C++ support is more prevalent
  
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceReduce::Reduce(d_temp_storage, temp_storage_bytes,
              d_in, d_out, num_items, reduction_op, identity,
              stream, debug_synchronous);
      }
  
      printf("\t timing_timing_iterations: %d, temp_storage_bytes: %lld
  ",
          timing_timing_iterations, temp_storage_bytes);
  
      return error;
  }
  
  /**
   * Dispatch to sum entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::Sum            reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceReduce::Sum(d_temp_storage, temp_storage_bytes, d_in, d_out, num_items, stream, debug_synchronous);
      }
  
      printf("\t timing_timing_iterations: %d, temp_storage_bytes: %lld
  ",
          timing_timing_iterations, temp_storage_bytes);
  
      return error;
  }
  
  /**
   * Dispatch to min entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::Min            reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceReduce::Min(d_temp_storage, temp_storage_bytes, d_in, d_out, num_items, stream, debug_synchronous);
      }
  
      printf("\t timing_timing_iterations: %d, temp_storage_bytes: %lld
  ",
          timing_timing_iterations, temp_storage_bytes);
  
      return error;
  }
  
  /**
   * Dispatch to max entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::Max            reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceReduce::Max(d_temp_storage, temp_storage_bytes, d_in, d_out, num_items, stream, debug_synchronous);
      }
  
      printf("\t timing_timing_iterations: %d, temp_storage_bytes: %lld
  ",
          timing_timing_iterations, temp_storage_bytes);
  
      return error;
  }
  
  /**
   * Dispatch to argmin entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::ArgMin         reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceReduce::ArgMin(d_temp_storage, temp_storage_bytes, d_in, d_out, num_items, stream, debug_synchronous);
      }
  
      printf("\t timing_timing_iterations: %d, temp_storage_bytes: %lld
  ",
          timing_timing_iterations, temp_storage_bytes);
  
      return error;
  }
  
  /**
   * Dispatch to argmax entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::ArgMax         reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceReduce::ArgMax(d_temp_storage, temp_storage_bytes, d_in, d_out, num_items, stream, debug_synchronous);
      }
  
      printf("\t timing_timing_iterations: %d, temp_storage_bytes: %lld
  ",
          timing_timing_iterations, temp_storage_bytes);
  
      return error;
  }
  
  
  //---------------------------------------------------------------------
  // Dispatch to different CUB DeviceSegmentedReduce entrypoints
  //---------------------------------------------------------------------
  
  /**
   * Dispatch to reduce entrypoint (custom-max)
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT, typename ReductionOpT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB_SEGMENTED>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      ReductionOpT        reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // The input value type
      typedef typename std::iterator_traits<InputIteratorT>::value_type InputT;
  
      // The output value type
      typedef typename If<(Equals<typename std::iterator_traits<OutputIteratorT>::value_type, void>::VALUE),  // OutputT =  (if output iterator's value type is void) ?
          typename std::iterator_traits<InputIteratorT>::value_type,                                          // ... then the input iterator's value type,
          typename std::iterator_traits<OutputIteratorT>::value_type>::Type OutputT;                          // ... else the output iterator's value type
  
      // Max-identity
      OutputT identity = Traits<InputT>::Lowest(); // replace with std::numeric_limits<OutputT>::lowest() when C++ support is more prevalent
  
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceSegmentedReduce::Reduce(d_temp_storage, temp_storage_bytes,
              d_in, d_out, max_segments, d_segment_offsets, d_segment_offsets + 1, reduction_op, identity,
              stream, debug_synchronous);
      }
      return error;
  }
  
  /**
   * Dispatch to sum entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB_SEGMENTED>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::Sum            reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceSegmentedReduce::Sum(d_temp_storage, temp_storage_bytes,
              d_in, d_out, max_segments, d_segment_offsets, d_segment_offsets + 1,
              stream, debug_synchronous);
      }
      return error;
  }
  
  /**
   * Dispatch to min entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB_SEGMENTED>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::Min            reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceSegmentedReduce::Min(d_temp_storage, temp_storage_bytes,
              d_in, d_out, max_segments, d_segment_offsets, d_segment_offsets + 1,
              stream, debug_synchronous);
      }
      return error;
  }
  
  /**
   * Dispatch to max entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB_SEGMENTED>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::Max            reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceSegmentedReduce::Max(d_temp_storage, temp_storage_bytes,
              d_in, d_out, max_segments, d_segment_offsets, d_segment_offsets + 1,
              stream, debug_synchronous);
      }
      return error;
  }
  
  /**
   * Dispatch to argmin entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB_SEGMENTED>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::ArgMin         reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceSegmentedReduce::ArgMin(d_temp_storage, temp_storage_bytes,
              d_in, d_out, max_segments, d_segment_offsets, d_segment_offsets + 1,
              stream, debug_synchronous);
      }
      return error;
  }
  
  /**
   * Dispatch to argmax entrypoint
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB_SEGMENTED>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      cub::ArgMax         reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to device reduction directly
      cudaError_t error = cudaSuccess;
      for (int i = 0; i < timing_timing_iterations; ++i)
      {
          error = DeviceSegmentedReduce::ArgMax(d_temp_storage, temp_storage_bytes,
              d_in, d_out, max_segments, d_segment_offsets, d_segment_offsets + 1,
              stream, debug_synchronous);
      }
      return error;
  }
  
  
  //---------------------------------------------------------------------
  // Dispatch to different Thrust entrypoints
  //---------------------------------------------------------------------
  
  /**
   * Dispatch to reduction entrypoint (min or max specialization)
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT, typename ReductionOpT>
  cudaError_t Dispatch(
      Int2Type<THRUST>    dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      ReductionOpT         reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // The output value type
      typedef typename If<(Equals<typename std::iterator_traits<OutputIteratorT>::value_type, void>::VALUE),  // OutputT =  (if output iterator's value type is void) ?
          typename std::iterator_traits<InputIteratorT>::value_type,                                          // ... then the input iterator's value type,
          typename std::iterator_traits<OutputIteratorT>::value_type>::Type OutputT;                          // ... else the output iterator's value type
  
      if (d_temp_storage == 0)
      {
          temp_storage_bytes = 1;
      }
      else
      {
          OutputT init;
          CubDebugExit(cudaMemcpy(&init, d_in + 0, sizeof(OutputT), cudaMemcpyDeviceToHost));
  
          thrust::device_ptr<OutputT> d_in_wrapper(d_in);
          OutputT retval;
          for (int i = 0; i < timing_timing_iterations; ++i)
          {
              retval = thrust::reduce(d_in_wrapper, d_in_wrapper + num_items, init, reduction_op);
          }
  
          if (!Equals<OutputIteratorT, DiscardOutputIterator<int> >::VALUE)
              CubDebugExit(cudaMemcpy(d_out, &retval, sizeof(OutputT), cudaMemcpyHostToDevice));
      }
  
      return cudaSuccess;
  }
  
  /**
   * Dispatch to reduction entrypoint (sum specialization)
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT>
  cudaError_t Dispatch(
      Int2Type<THRUST>    dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      Sum                 reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // The output value type
      typedef typename If<(Equals<typename std::iterator_traits<OutputIteratorT>::value_type, void>::VALUE),  // OutputT =  (if output iterator's value type is void) ?
          typename std::iterator_traits<InputIteratorT>::value_type,                                          // ... then the input iterator's value type,
          typename std::iterator_traits<OutputIteratorT>::value_type>::Type OutputT;                          // ... else the output iterator's value type
  
      if (d_temp_storage == 0)
      {
          temp_storage_bytes = 1;
      }
      else
      {
          thrust::device_ptr<OutputT> d_in_wrapper(d_in);
          OutputT retval;
          for (int i = 0; i < timing_timing_iterations; ++i)
          {
              retval = thrust::reduce(d_in_wrapper, d_in_wrapper + num_items);
          }
  
          if (!Equals<OutputIteratorT, DiscardOutputIterator<int> >::VALUE)
              CubDebugExit(cudaMemcpy(d_out, &retval, sizeof(OutputT), cudaMemcpyHostToDevice));
      }
  
      return cudaSuccess;
  }
  
  
  //---------------------------------------------------------------------
  // CUDA nested-parallelism test kernel
  //---------------------------------------------------------------------
  
  /**
   * Simple wrapper kernel to invoke DeviceReduce
   */
  template <
      typename            InputIteratorT,
      typename            OutputIteratorT,
      typename            OffsetIteratorT,
      typename            ReductionOpT>
  __global__ void CnpDispatchKernel(
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t              temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      ReductionOpT        reduction_op,
      bool                debug_synchronous)
  {
  #ifndef CUB_CDP
      *d_cdp_error = cudaErrorNotSupported;
  #else
      *d_cdp_error = Dispatch(Int2Type<CUB>(), timing_timing_iterations, d_temp_storage_bytes, d_cdp_error, d_temp_storage, temp_storage_bytes,
          d_in, d_out, num_items, max_segments, d_segment_offsets, reduction_op, 0, debug_synchronous);
      *d_temp_storage_bytes = temp_storage_bytes;
  #endif
  }
  
  
  /**
   * Dispatch to CUB_CDP kernel
   */
  template <typename InputIteratorT, typename OutputIteratorT, typename OffsetIteratorT, typename ReductionOpT>
  CUB_RUNTIME_FUNCTION __forceinline__
  cudaError_t Dispatch(
      Int2Type<CUB_CDP>       dispatch_to,
      int                 timing_timing_iterations,
      size_t              *d_temp_storage_bytes,
      cudaError_t         *d_cdp_error,
  
      void*               d_temp_storage,
      size_t&             temp_storage_bytes,
      InputIteratorT      d_in,
      OutputIteratorT     d_out,
      int                 num_items,
      int                 max_segments,
      OffsetIteratorT     d_segment_offsets,
      ReductionOpT        reduction_op,
      cudaStream_t        stream,
      bool                debug_synchronous)
  {
      // Invoke kernel to invoke device-side dispatch
      CnpDispatchKernel<<<1,1>>>(timing_timing_iterations, d_temp_storage_bytes, d_cdp_error, d_temp_storage, temp_storage_bytes,
          d_in, d_out, num_items, max_segments, d_segment_offsets, reduction_op, debug_synchronous);
  
      // Copy out temp_storage_bytes
      CubDebugExit(cudaMemcpy(&temp_storage_bytes, d_temp_storage_bytes, sizeof(size_t) * 1, cudaMemcpyDeviceToHost));
  
      // Copy out error
      cudaError_t retval;
      CubDebugExit(cudaMemcpy(&retval, d_cdp_error, sizeof(cudaError_t) * 1, cudaMemcpyDeviceToHost));
      return retval;
  }
  
  
  
  //---------------------------------------------------------------------
  // Problem generation
  //---------------------------------------------------------------------
  
  /// Initialize problem
  template <typename InputT>
  void Initialize(
      GenMode         gen_mode,
      InputT          *h_in,
      int             num_items)
  {
      for (int i = 0; i < num_items; ++i)
      {
          InitValue(gen_mode, h_in[i], i);
      }
  
      if (g_verbose_input)
      {
          printf("Input:
  ");
          DisplayResults(h_in, num_items);
          printf("
  
  ");
      }
  }
  
  
  /// Solve problem (max/custom-max functor)
  template <typename ReductionOpT, typename InputT, typename _OutputT>
  struct Solution
  {
      typedef _OutputT OutputT;
  
      template <typename HostInputIteratorT, typename OffsetT, typename OffsetIteratorT>
      static void Solve(HostInputIteratorT h_in, OutputT *h_reference, OffsetT num_segments, OffsetIteratorT h_segment_offsets,
          ReductionOpT reduction_op)
      {
          for (int i = 0; i < num_segments; ++i)
          {
              OutputT aggregate = Traits<InputT>::Lowest(); // replace with std::numeric_limits<OutputT>::lowest() when C++ support is more prevalent
              for (int j = h_segment_offsets[i]; j < h_segment_offsets[i + 1]; ++j)
                  aggregate = reduction_op(aggregate, OutputT(h_in[j]));
              h_reference[i] = aggregate;
          }
      }
  };
  
  /// Solve problem (min functor)
  template <typename InputT, typename _OutputT>
  struct Solution<cub::Min, InputT, _OutputT>
  {
      typedef _OutputT OutputT;
  
      template <typename HostInputIteratorT, typename OffsetT, typename OffsetIteratorT>
      static void Solve(HostInputIteratorT h_in, OutputT *h_reference, OffsetT num_segments, OffsetIteratorT h_segment_offsets,
          cub::Min reduction_op)
      {
          for (int i = 0; i < num_segments; ++i)
          {
              OutputT aggregate = Traits<InputT>::Max();    // replace with std::numeric_limits<OutputT>::max() when C++ support is more prevalent
              for (int j = h_segment_offsets[i]; j < h_segment_offsets[i + 1]; ++j)
                  aggregate = reduction_op(aggregate, OutputT(h_in[j]));
              h_reference[i] = aggregate;
          }
      }
  };
  
  
  /// Solve problem (sum functor)
  template <typename InputT, typename _OutputT>
  struct Solution<cub::Sum, InputT, _OutputT>
  {
      typedef _OutputT OutputT;
  
      template <typename HostInputIteratorT, typename OffsetT, typename OffsetIteratorT>
      static void Solve(HostInputIteratorT h_in, OutputT *h_reference, OffsetT num_segments, OffsetIteratorT h_segment_offsets,
          cub::Sum reduction_op)
      {
          for (int i = 0; i < num_segments; ++i)
          {
              OutputT aggregate;
              InitValue(INTEGER_SEED, aggregate, 0);
              for (int j = h_segment_offsets[i]; j < h_segment_offsets[i + 1]; ++j)
                  aggregate = reduction_op(aggregate, OutputT(h_in[j]));
              h_reference[i] = aggregate;
          }
      }
  };
  
  /// Solve problem (argmin functor)
  template <typename InputValueT, typename OutputValueT>
  struct Solution<cub::ArgMin, InputValueT, OutputValueT>
  {
      typedef KeyValuePair<int, OutputValueT> OutputT;
  
      template <typename HostInputIteratorT, typename OffsetT, typename OffsetIteratorT>
      static void Solve(HostInputIteratorT h_in, OutputT *h_reference, OffsetT num_segments, OffsetIteratorT h_segment_offsets,
          cub::ArgMin reduction_op)
      {
          for (int i = 0; i < num_segments; ++i)
          {
              OutputT aggregate(1, Traits<InputValueT>::Max()); // replace with std::numeric_limits<OutputT>::max() when C++ support is more prevalent
              for (int j = h_segment_offsets[i]; j < h_segment_offsets[i + 1]; ++j)
              {
                  OutputT item(j - h_segment_offsets[i], OutputValueT(h_in[j]));
                  aggregate = reduction_op(aggregate, item);
              }
              h_reference[i] = aggregate;
          }
      }
  };
  
  
  /// Solve problem (argmax functor)
  template <typename InputValueT, typename OutputValueT>
  struct Solution<cub::ArgMax, InputValueT, OutputValueT>
  {
      typedef KeyValuePair<int, OutputValueT> OutputT;
  
      template <typename HostInputIteratorT, typename OffsetT, typename OffsetIteratorT>
      static void Solve(HostInputIteratorT h_in, OutputT *h_reference, OffsetT num_segments, OffsetIteratorT h_segment_offsets,
          cub::ArgMax reduction_op)
      {
          for (int i = 0; i < num_segments; ++i)
          {
              OutputT aggregate(1, Traits<InputValueT>::Lowest()); // replace with std::numeric_limits<OutputT>::lowest() when C++ support is more prevalent
              for (int j = h_segment_offsets[i]; j < h_segment_offsets[i + 1]; ++j)
              {
                  OutputT item(j - h_segment_offsets[i], OutputValueT(h_in[j]));
                  aggregate = reduction_op(aggregate, item);
              }
              h_reference[i] = aggregate;
          }
      }
  };
  
  
  //---------------------------------------------------------------------
  // Problem generation
  //---------------------------------------------------------------------
  
  /// Test DeviceReduce for a given problem input
  template <
      typename                BackendT,
      typename                DeviceInputIteratorT,
      typename                DeviceOutputIteratorT,
      typename                HostReferenceIteratorT,
      typename                OffsetT,
      typename                OffsetIteratorT,
      typename                ReductionOpT>
  void Test(
      BackendT                backend,
      DeviceInputIteratorT    d_in,
      DeviceOutputIteratorT   d_out,
      OffsetT                 num_items,
      OffsetT                 num_segments,
      OffsetIteratorT         d_segment_offsets,
      ReductionOpT            reduction_op,
      HostReferenceIteratorT  h_reference)
  {
      // Input data types
      typedef typename std::iterator_traits<DeviceInputIteratorT>::value_type InputT;
  
      // Allocate CUB_CDP device arrays for temp storage size and error
      size_t          *d_temp_storage_bytes = NULL;
      cudaError_t     *d_cdp_error = NULL;
      CubDebugExit(g_allocator.DeviceAllocate((void**)&d_temp_storage_bytes,  sizeof(size_t) * 1));
      CubDebugExit(g_allocator.DeviceAllocate((void**)&d_cdp_error,           sizeof(cudaError_t) * 1));
  
      // Inquire temp device storage
      void            *d_temp_storage = NULL;
      size_t          temp_storage_bytes = 0;
      CubDebugExit(Dispatch(backend, 1,
          d_temp_storage_bytes, d_cdp_error, d_temp_storage, temp_storage_bytes,
          d_in, d_out, num_items, num_segments, d_segment_offsets,
          reduction_op, 0, true));
  
      // Allocate temp device storage
      CubDebugExit(g_allocator.DeviceAllocate(&d_temp_storage, temp_storage_bytes));
  
      // Run warmup/correctness iteration
      CubDebugExit(Dispatch(backend, 1,
          d_temp_storage_bytes, d_cdp_error, d_temp_storage, temp_storage_bytes,
          d_in, d_out, num_items, num_segments, d_segment_offsets,
          reduction_op, 0, true));
  
      // Check for correctness (and display results, if specified)
      int compare = CompareDeviceResults(h_reference, d_out, num_segments, g_verbose, g_verbose);
      printf("\t%s", compare ? "FAIL" : "PASS");
  
      // Flush any stdout/stderr
      fflush(stdout);
      fflush(stderr);
  
      // Performance
      if (g_timing_iterations > 0)
      {
          GpuTimer gpu_timer;
          gpu_timer.Start();
  
          CubDebugExit(Dispatch(backend, g_timing_iterations,
              d_temp_storage_bytes, d_cdp_error, d_temp_storage, temp_storage_bytes,
              d_in, d_out, num_items, num_segments, d_segment_offsets,
              reduction_op, 0, false));
  
          gpu_timer.Stop();
          float elapsed_millis = gpu_timer.ElapsedMillis();
  
          // Display performance
          float avg_millis = elapsed_millis / g_timing_iterations;
          float giga_rate = float(num_items) / avg_millis / 1000.0f / 1000.0f;
          float giga_bandwidth = giga_rate * sizeof(InputT);
          printf(", %.3f avg ms, %.3f billion items/s, %.3f logical GB/s", avg_millis, giga_rate, giga_bandwidth);
      }
  
      if (d_temp_storage_bytes) CubDebugExit(g_allocator.DeviceFree(d_temp_storage_bytes));
      if (d_cdp_error) CubDebugExit(g_allocator.DeviceFree(d_cdp_error));
      if (d_temp_storage) CubDebugExit(g_allocator.DeviceFree(d_temp_storage));
  
      // Correctness asserts
      AssertEquals(0, compare);
  }
  
  
  /// Test DeviceReduce
  template <
      Backend                 BACKEND,
      typename                OutputValueT,
      typename                HostInputIteratorT,
      typename                DeviceInputIteratorT,
      typename                OffsetT,
      typename                OffsetIteratorT,
      typename                ReductionOpT>
  void SolveAndTest(
      HostInputIteratorT      h_in,
      DeviceInputIteratorT    d_in,
      OffsetT                 num_items,
      OffsetT                 num_segments,
      OffsetIteratorT         h_segment_offsets,
      OffsetIteratorT         d_segment_offsets,
      ReductionOpT            reduction_op)
  {
      typedef typename std::iterator_traits<DeviceInputIteratorT>::value_type     InputValueT;
      typedef Solution<ReductionOpT, InputValueT, OutputValueT>                   SolutionT;
      typedef typename SolutionT::OutputT                                         OutputT;
  
      printf("
  
  %s cub::DeviceReduce<%s> %d items (%s), %d segments
  ",
          (BACKEND == CUB_CDP) ? "CUB_CDP" : (BACKEND == THRUST) ? "Thrust" : (BACKEND == CUB_SEGMENTED) ? "CUB_SEGMENTED" : "CUB",
          typeid(ReductionOpT).name(), num_items, typeid(HostInputIteratorT).name(), num_segments);
      fflush(stdout);
  
      // Allocate and solve solution
      OutputT *h_reference = new OutputT[num_segments];
      SolutionT::Solve(h_in, h_reference, num_segments, h_segment_offsets, reduction_op);
  
      // Run with discard iterator
      DiscardOutputIterator<OffsetT> discard_itr;
      Test(Int2Type<BACKEND>(), d_in, discard_itr, num_items, num_segments, d_segment_offsets, reduction_op, h_reference);
  
      // Run with output data (cleared for sanity-check)
      OutputT *d_out = NULL;
      CubDebugExit(g_allocator.DeviceAllocate((void**)&d_out, sizeof(OutputT) * num_segments));
      CubDebugExit(cudaMemset(d_out, 0, sizeof(OutputT) * num_segments));
      Test(Int2Type<BACKEND>(), d_in, d_out, num_items, num_segments, d_segment_offsets, reduction_op, h_reference);
  
      // Cleanup
      if (d_out) CubDebugExit(g_allocator.DeviceFree(d_out));
      if (h_reference) delete[] h_reference;
  }
  
  
  /// Test specific problem type
  template <
      Backend         BACKEND,
      typename        InputT,
      typename        OutputT,
      typename        OffsetT,
      typename        ReductionOpT>
  void TestProblem(
      OffsetT         num_items,
      OffsetT         num_segments,
      GenMode         gen_mode,
      ReductionOpT    reduction_op)
  {
      printf("
  
  Initializing %d %s->%s (gen mode %d)... ", num_items, typeid(InputT).name(), typeid(OutputT).name(), gen_mode); fflush(stdout);
      fflush(stdout);
  
      // Initialize value data
      InputT* h_in = new InputT[num_items];
      Initialize(gen_mode, h_in, num_items);
  
      // Initialize segment data
      OffsetT *h_segment_offsets = new OffsetT[num_segments + 1];
      InitializeSegments(num_items, num_segments, h_segment_offsets, g_verbose_input);
  
      // Initialize device data
      OffsetT *d_segment_offsets      = NULL;
      InputT  *d_in                   = NULL;
      CubDebugExit(g_allocator.DeviceAllocate((void**)&d_in,              sizeof(InputT) * num_items));
      CubDebugExit(g_allocator.DeviceAllocate((void**)&d_segment_offsets, sizeof(OffsetT) * (num_segments + 1)));
      CubDebugExit(cudaMemcpy(d_in,               h_in,                   sizeof(InputT) * num_items, cudaMemcpyHostToDevice));
      CubDebugExit(cudaMemcpy(d_segment_offsets,  h_segment_offsets,      sizeof(OffsetT) * (num_segments + 1), cudaMemcpyHostToDevice));
  
      SolveAndTest<BACKEND, OutputT>(h_in, d_in, num_items, num_segments, h_segment_offsets, d_segment_offsets, reduction_op);
  
      if (h_segment_offsets)  delete[] h_segment_offsets;
      if (d_segment_offsets)  CubDebugExit(g_allocator.DeviceFree(d_segment_offsets));
      if (h_in)               delete[] h_in;
      if (d_in)               CubDebugExit(g_allocator.DeviceFree(d_in));
  }
  
  
  /// Test different operators
  template <
      Backend             BACKEND,
      typename            OutputT,
      typename            HostInputIteratorT,
      typename            DeviceInputIteratorT,
      typename            OffsetT,
      typename            OffsetIteratorT>
  void TestByOp(
      HostInputIteratorT      h_in,
      DeviceInputIteratorT    d_in,
      OffsetT                 num_items,
      OffsetT                 num_segments,
      OffsetIteratorT         h_segment_offsets,
      OffsetIteratorT         d_segment_offsets)
  {
      SolveAndTest<BACKEND, OutputT>(h_in, d_in, num_items, num_segments, h_segment_offsets, d_segment_offsets, CustomMax());
      SolveAndTest<BACKEND, OutputT>(h_in, d_in, num_items, num_segments, h_segment_offsets, d_segment_offsets, Sum());
      SolveAndTest<BACKEND, OutputT>(h_in, d_in, num_items, num_segments, h_segment_offsets, d_segment_offsets, Min());
      SolveAndTest<BACKEND, OutputT>(h_in, d_in, num_items, num_segments, h_segment_offsets, d_segment_offsets, ArgMin());
      SolveAndTest<BACKEND, OutputT>(h_in, d_in, num_items, num_segments, h_segment_offsets, d_segment_offsets, Max());
      SolveAndTest<BACKEND, OutputT>(h_in, d_in, num_items, num_segments, h_segment_offsets, d_segment_offsets, ArgMax());
  }
  
  
  /// Test different backends
  template <
      typename    InputT,
      typename    OutputT,
      typename    OffsetT>
  void TestByBackend(
      OffsetT     num_items,
      OffsetT     max_segments,
      GenMode     gen_mode)
  {
      // Initialize host data
      printf("
  
  Initializing %d %s -> %s (gen mode %d)... ",
          num_items, typeid(InputT).name(), typeid(OutputT).name(), gen_mode); fflush(stdout);
  
      InputT  *h_in               = new InputT[num_items];
      OffsetT *h_segment_offsets  = new OffsetT[max_segments + 1];
      Initialize(gen_mode, h_in, num_items);
  
      // Initialize device data
      InputT  *d_in               = NULL;
      OffsetT *d_segment_offsets  = NULL;
      CubDebugExit(g_allocator.DeviceAllocate((void**)&d_in, sizeof(InputT) * num_items));
      CubDebugExit(g_allocator.DeviceAllocate((void**)&d_segment_offsets, sizeof(OffsetT) * (max_segments + 1)));
      CubDebugExit(cudaMemcpy(d_in, h_in, sizeof(InputT) * num_items, cudaMemcpyHostToDevice));
  
      //
      // Test single-segment implementations
      //
  
      InitializeSegments(num_items, 1, h_segment_offsets, g_verbose_input);
  
      // Page-aligned-input tests
      TestByOp<CUB, OutputT>(h_in, d_in, num_items, 1, h_segment_offsets, (OffsetT*) NULL);                 // Host-dispatch
  #ifdef CUB_CDP
      TestByOp<CUB_CDP, OutputT>(h_in, d_in, num_items, 1, h_segment_offsets, (OffsetT*) NULL);             // Device-dispatch
  #endif
  
      // Non-page-aligned-input tests
      if (num_items > 1)
      {
          InitializeSegments(num_items - 1, 1, h_segment_offsets, g_verbose_input);
          TestByOp<CUB, OutputT>(h_in + 1, d_in + 1, num_items - 1, 1, h_segment_offsets, (OffsetT*) NULL);
      }
  
      //
      // Test segmented implementation
      //
  
      // Right now we assign a single thread block to each segment, so lets keep it to under 128K items per segment
      int max_items_per_segment = 128000;
  
      for (int num_segments = (num_items + max_items_per_segment - 1) / max_items_per_segment;
          num_segments < max_segments;
          num_segments = (num_segments * 32) + 1)
      {
          // Test with segment pointer
          InitializeSegments(num_items, num_segments, h_segment_offsets, g_verbose_input);
          CubDebugExit(cudaMemcpy(d_segment_offsets, h_segment_offsets, sizeof(OffsetT) * (num_segments + 1), cudaMemcpyHostToDevice));
          TestByOp<CUB_SEGMENTED, OutputT>(
              h_in, d_in, num_items, num_segments, h_segment_offsets, d_segment_offsets);
  
          // Test with segment iterator
          typedef CastOp<OffsetT> IdentityOpT;
          IdentityOpT identity_op;
          TransformInputIterator<OffsetT, IdentityOpT, OffsetT*, OffsetT> h_segment_offsets_itr(
              h_segment_offsets,
              identity_op);
         TransformInputIterator<OffsetT, IdentityOpT, OffsetT*, OffsetT> d_segment_offsets_itr(
              d_segment_offsets,
              identity_op);
  
          TestByOp<CUB_SEGMENTED, OutputT>(
              h_in, d_in, num_items, num_segments, h_segment_offsets_itr, d_segment_offsets_itr);
      }
  
      if (h_in)               delete[] h_in;
      if (h_segment_offsets)  delete[] h_segment_offsets;
      if (d_in)               CubDebugExit(g_allocator.DeviceFree(d_in));
      if (d_segment_offsets)  CubDebugExit(g_allocator.DeviceFree(d_segment_offsets));
  }
  
  
  /// Test different input-generation modes
  template <
      typename InputT,
      typename OutputT,
      typename OffsetT>
  void TestByGenMode(
      OffsetT num_items,
      OffsetT max_segments)
  {
      //
      // Test pointer support using different input-generation modes
      //
  
      TestByBackend<InputT, OutputT>(num_items, max_segments, UNIFORM);
      TestByBackend<InputT, OutputT>(num_items, max_segments, INTEGER_SEED);
      TestByBackend<InputT, OutputT>(num_items, max_segments, RANDOM);
  
      //
      // Test iterator support using a constant-iterator and SUM
      //
  
      InputT val;
      InitValue(UNIFORM, val, 0);
      ConstantInputIterator<InputT, OffsetT> h_in(val);
  
      OffsetT *h_segment_offsets = new OffsetT[1 + 1];
      InitializeSegments(num_items, 1, h_segment_offsets, g_verbose_input);
  
      SolveAndTest<CUB, OutputT>(h_in, h_in, num_items, 1, h_segment_offsets, (OffsetT*) NULL, Sum());
  #ifdef CUB_CDP
      SolveAndTest<CUB_CDP, OutputT>(h_in, h_in, num_items, 1, h_segment_offsets, (OffsetT*) NULL, Sum());
  #endif
  
      if (h_segment_offsets) delete[] h_segment_offsets;
  }
  
  
  /// Test different problem sizes
  template <
      typename InputT,
      typename OutputT,
      typename OffsetT>
  struct TestBySize
  {
      OffsetT max_items;
      OffsetT max_segments;
  
      TestBySize(OffsetT max_items, OffsetT max_segments) :
          max_items(max_items),
          max_segments(max_segments)
      {}
  
      template <typename ActivePolicyT>
      cudaError_t Invoke()
      {
          //
          // Black-box testing on all backends
          //
  
          // Test 0, 1, many
          TestByGenMode<InputT, OutputT>(0,           max_segments);
          TestByGenMode<InputT, OutputT>(1,           max_segments);
          TestByGenMode<InputT, OutputT>(max_items,   max_segments);
  
          // Test random problem sizes from a log-distribution [8, max_items-ish)
          int     num_iterations = 8;
          double  max_exp = log(double(max_items)) / log(double(2.0));
          for (int i = 0; i < num_iterations; ++i)
          {
              OffsetT num_items = (OffsetT) pow(2.0, RandomValue(max_exp - 3.0) + 3.0);
              TestByGenMode<InputT, OutputT>(num_items, max_segments);
          }
  
          //
          // White-box testing of single-segment problems around specific sizes
          //
  
          // Tile-boundaries: multiple blocks, one tile per block
          OffsetT tile_size = ActivePolicyT::ReducePolicy::BLOCK_THREADS * ActivePolicyT::ReducePolicy::ITEMS_PER_THREAD;
          TestProblem<CUB, InputT, OutputT>(tile_size * 4,  1,      RANDOM, Sum());
          TestProblem<CUB, InputT, OutputT>(tile_size * 4 + 1, 1,   RANDOM, Sum());
          TestProblem<CUB, InputT, OutputT>(tile_size * 4 - 1, 1,   RANDOM, Sum());
  
          // Tile-boundaries: multiple blocks, multiple tiles per block
          OffsetT sm_occupancy = 32;
          OffsetT occupancy = tile_size * sm_occupancy * g_sm_count;
          TestProblem<CUB, InputT, OutputT>(occupancy,  1,      RANDOM, Sum());
          TestProblem<CUB, InputT, OutputT>(occupancy + 1, 1,   RANDOM, Sum());
          TestProblem<CUB, InputT, OutputT>(occupancy - 1, 1,   RANDOM, Sum());
  
          return cudaSuccess;
      }
  };
  
  
  /// Test problem type
  template <
      typename    InputT,
      typename    OutputT,
      typename    OffsetT>
  void TestType(
      OffsetT     max_items,
      OffsetT     max_segments)
  {
      typedef typename DeviceReducePolicy<OutputT, OffsetT, cub::Sum>::MaxPolicy MaxPolicyT;
  
      TestBySize<InputT, OutputT, OffsetT> dispatch(max_items, max_segments);
  
      MaxPolicyT::Invoke(g_ptx_version, dispatch);
  }
  
  
  //---------------------------------------------------------------------
  // Main
  //---------------------------------------------------------------------
  
  
  /**
   * Main
   */
  int main(int argc, char** argv)
  {
      typedef int OffsetT;
  
      OffsetT max_items       = 27000000;
      OffsetT max_segments    = 34000;
  
      // Initialize command line
      CommandLineArgs args(argc, argv);
      g_verbose = args.CheckCmdLineFlag("v");
      g_verbose_input = args.CheckCmdLineFlag("v2");
      args.GetCmdLineArgument("n", max_items);
      args.GetCmdLineArgument("s", max_segments);
      args.GetCmdLineArgument("i", g_timing_iterations);
      args.GetCmdLineArgument("repeat", g_repeat);
  
      // Print usage
      if (args.CheckCmdLineFlag("help"))
      {
          printf("%s "
              "[--n=<input items> "
              "[--s=<num segments> "
              "[--i=<timing iterations> "
              "[--device=<device-id>] "
              "[--repeat=<repetitions of entire test suite>]"
              "[--v] "
              "[--cdp]"
              "
  ", argv[0]);
          exit(0);
      }
  
      // Initialize device
      CubDebugExit(args.DeviceInit());
  
      // Get ptx version
      CubDebugExit(PtxVersion(g_ptx_version));
  
      // Get SM count
      g_sm_count = args.deviceProp.multiProcessorCount;
  
      std::numeric_limits<float>::max();
  
  #ifdef QUICKER_TEST
  
      // Compile/run basic test
  
  
  
      TestProblem<CUB, int, int>(     max_items, 1, RANDOM, Sum());
  
      TestProblem<CUB, char, int>(    max_items, 1, RANDOM, Sum());
  
      TestProblem<CUB, int, int>(     max_items, 1, RANDOM, ArgMax());
  
      TestProblem<CUB, float, float>( max_items, 1, RANDOM, Sum());
  
      TestProblem<CUB_SEGMENTED, int, int>(max_items, max_segments, RANDOM, Sum());
  
  
  #elif defined(QUICK_TEST)
  
      // Compile/run quick comparison tests
  
      TestProblem<CUB, char, char>(         max_items * 4, 1, UNIFORM, Sum());
      TestProblem<THRUST, char, char>(      max_items * 4, 1, UNIFORM, Sum());
  
      printf("
  ----------------------------
  ");
      TestProblem<CUB, short, short>(        max_items * 2, 1, UNIFORM, Sum());
      TestProblem<THRUST, short, short>(     max_items * 2, 1, UNIFORM, Sum());
  
      printf("
  ----------------------------
  ");
      TestProblem<CUB, int, int>(          max_items,     1, UNIFORM, Sum());
      TestProblem<THRUST, int, int>(       max_items,     1, UNIFORM, Sum());
  
      printf("
  ----------------------------
  ");
      TestProblem<CUB, long long, long long>(    max_items / 2, 1, UNIFORM, Sum());
      TestProblem<THRUST, long long, long long>( max_items / 2, 1, UNIFORM, Sum());
  
      printf("
  ----------------------------
  ");
      TestProblem<CUB, TestFoo, TestFoo>(      max_items / 4, 1, UNIFORM, Max());
      TestProblem<THRUST, TestFoo, TestFoo>(   max_items / 4, 1, UNIFORM, Max());
  
  #else
  
      // Compile/run thorough tests
      for (int i = 0; i <= g_repeat; ++i)
      {
          // Test different input types
          TestType<char, char>(max_items, max_segments);
  
          TestType<unsigned char, unsigned char>(max_items, max_segments);
  
          TestType<char, int>(max_items, max_segments);
  
  //        TestType<short, short>(max_items, max_segments);
  //        TestType<int, int>(max_items, max_segments);
  //        TestType<long, long>(max_items, max_segments);
  //        TestType<long long, long long>(max_items, max_segments);
  //
  //        TestType<uchar2, uchar2>(max_items, max_segments);
  //        TestType<uint2, uint2>(max_items, max_segments);
  //        TestType<ulonglong2, ulonglong2>(max_items, max_segments);
  //        TestType<ulonglong4, ulonglong4>(max_items, max_segments);
  //
  //        TestType<TestFoo, TestFoo>(max_items, max_segments);
  //        TestType<TestBar, TestBar>(max_items, max_segments);
  
      }
  
  #endif
  
  
      printf("
  ");
      return 0;
  }